[bandit420]

the way fishing works in FFXIV is this. you can only fish in one "fishing hole" for so long before it gives you the "the fish sense something amiss" message, the average time you can fish in one location is between 30-45min. after the message appears you have to fish in a different "fishing hole" to reset the first location, you only have to cast your line into the new fishing location to reset the first one so no need to actually fish or catch anything. i am a avid fisher and have done and caught everything possible, this is how i setup fishing and has worked flawlessly for almost a year now.

set you fishing marker in the fishing hole your aiming for. i personally put a marker time of 1200-1500 and set 2 markers for same location one just a few meters away from first but in same area. then you set a 3rd marker in a diffrent fishing loacation that is a good distance away from your first location.
set that marker to a low time anywhere from 30-120. so what this does is it will fish in your first location for 30-40min between the 2 markers then run to the third location and cast your line into water for a few seconds then leave and start fishing in first spot again for another 30-40min.

i have not run into the error message one time since ive done this and im now 3 HQ fish away from getting my i90 fishing rod